Automatic hydraulic-mechanical follow-up control system



pri 3, E951 J. P. ANDERSON 2,547,552

AUTOMATTO HYDRAULIC-MECHANICAL FOLLOW-UP CONTROL SYSTEM 2 Sheets-Sheet 1Filed May l1, 1948 com 7 l/ oom oo. Al a5. oo

V.John P. Anderson IN VEN TOR.

PATENT ATTORNEY Filed May l1, 1948 Fig. 5

P.ANDERSON J. AUTOMATIC HYDRAULIC-MECHANICAL FOLLOW-UP CONTROL SYSTEM 2Sheets-Sheet 2 John P. Anderson JNVENTOR.

J/ PATENT ATTORNEY forces.

rITD STA'ES NT iFiCE Autor/tarro meantime-MECHANICAL roLLovv-'nr ocNTnoLsys'rnlu John P. AndersonffFernwood, Calif., assigner to `North AmericanAviation, Inc.

ApplicatiOnll/ay "11, ll948, Serial Nog-26,353

(Cl. 12b-41) l1 Claims.

l 'The present inventionrelates to remote control fsystemsand'moreparticularly to improve- K ments in followup `controls fof thehydraulicmechanical type.

In remote `control systems, and particularly in aircraft, it isfrequently desirable to position ya remdteelement, vorsurfecey by meansof amanti- -ally controlled hydraulic -mot'or with relatively highboost, or mechanical advantage, in :order that-1a ilarge element can 'bereadily'lncwedY bythe application of `relatively Ysmall manual Vcontrol.It is also desirable in such installations to follow-up thedisplacement or movement of the'movable element and when Vthe elementlhas been properly positioned 4tolretainthe same by suitable mechanical-means While the hydraulic portion :of the system is relieved ofthenecessity f maintaining further lhigh fluid pressures orpowenconsumi-ng Work 'in yorder to hold the element in the desiredposition. The presentinvem tion i-s accordingly directed to theprovisionof an improved remote control system -Whichutilizes -a pre-'selectedlhandle #position control With an "automatic shut-oft of hydraulic powerto the u'id motor' -unit -vv'hen Ithe pre-'selected Y-pc sitionoi thecontrolis reached; and Ifurther to automatically 1 return the hydraulicselector 'valve to its neutral position -to 'thereby 2allow freecirculation of the `iiuld in the pumpportion of the Vhydraulic system."Ihe present invention is directed to improvements in such controlsystems and-includes in addition to the hydraulic and mechanical4:follow-ina assemblies an improved manual `controlfmechanism and itsinterconnection with the y'hydraulic selector valve for the control ofthe 4h'yd'raulic 'motor and its cooperative opera-tion with themechanical portion-s of the system.

t is, accordingly, a major object `of 'the Vpresent invention to provide:anim-proved follow-'up vsystem for theremote 'control cfamovable-element. -A further objective resides in the vprovision of anA'improved hydraulicgmechanical follow- Yup *arrangement in which theadvantages V-o'f fthe "hydraulic system areutlized'to increaserelatively smallpilotfcontrol forces vto a sufficient extent to move thecontrolled element into its displaced PUH. A `'fur'tlfier object residesin'providing va mechanical @110V/ up assembly which is .mmh

'connected i'ivith vthe y'manual control Arnechanism and the hydraulic-selector'valveinfan improved manner which simplifies the manualoperation by a fool-proof andfea'sil'y operated mechanism.

It is a further object of this invention to provide a control systemwhich utilizes a pre-selected handleposition control Awith an automaticshutoff of 'hydraulic power 'to -the operated 'unit when 'the"pre-,selected :position :is reached. -It is a corollary objective 'toreturn the hydraulic selector vvalve to its neutral position after thepreselected position is reached, to thereby allow free circulation ofthe pressure luid Within that por tion of the hydraulic `system whichoy-passes lthe iiuid motor.

It is a further object of the present invention to provide an improvedinterconnection 'between the manually controlled mechanism and thehydraulic'selector valve of `the hydraulic system in which theinterconnectionincludes both centering and lost-motion means to uinsureproper -concurrent operation ef the control mechanism and lthe valve. It-isra still `further `object to provide an improved hydraulic-mechanicalfollow-up installation for use 'with a hydraulic system of ythe l lopen`center type.

Other objects and advantages of the present invention Will becomeobvious -to `those skilled in .the art after reading the followlingdescription taken together with the accompanying drawingsin which:

-Figz 1 is :a diagrammatic View of the improved hydraulic-mechanicalfollow-up system as applied 'to the-opera-tionof an aircraft ap;

Fig. 2 is an enlarged elevational :View of the manually controlledmechanism 4utiliz/ed in the systemfshown fin Fig. l;

Fig. 3 is a :cross-sectional View of th'e'mecha- `nism show-n in. Fig. 2as taken along thelires 3 3 thereof Fig. 4 is a detailed "View, partlybroken away,

'of the lostamotio'n means utilized in the systemof Fig. 1; and

Figs. V5, 6, :and 7 are diagrammatic views of the several operating.positions of the hydraulicfselector valve used in the system shown inFig. l.

Referring now to 'Fig. 1, k.the numeral I6 denotes a llaporother-movalole surface which'may `be p'ivotally or otherwise movablymounted adjacent the trailingedge ofanaircraft Wing. 'I-he Vflap LIE) isarranged to 'be hydraulically actuated by, the hydraulic vsystemgenerally indicated 'by the numeral 4Il fand, by means of a mechanicalfollow-up :system t2, ,the flap operating controll t3 is arranged toreturn the hydraulic selector valve Ul to its neutral position and'tomechanically retain -the adjusted position of the flap ill, with the'fluidimotor indicated at l5. 'While a Wingiiiap ill has Sheen selectedfor explanatory purposes, it will be understood that the improved systemand parts are also adapted .-for fuse With other displaceable elements.The'fiaplis shown'in this figure LAdeflected to 20 andthe presentmodification is based upon a five-position vflap which may be ladjustedinto its up or fully retracted position; its 10; its v20 Aor half-downposition :as shown; its 30; .and -fits 40 ,down, or fully extendedposition. The positions of adjustment other than the full line 2OOposition shown in Fig. 1, are also shown in this gure by broken lines,and it will be understood that the present invention, is equallyapplicable to aps or other movable surfaces which may be adjusted intomore or less positions and angles than are shown and described herein.

The lap l@ is provided with an arm or horn 65 which is pivotallyattached to the wing bracket Il by the pivot IS. 'Ihe flap I0 is alsoprovided with a pivot I9 to which is connected the hydraulic motor oractuating means I and the mechanical follow-up means l2 to be more fullydescribed below. The hydraulic actuating system II comprises essentiallythe manual control mechanism I3, the selector valve I4 and the actuatingmotor I5, and includes in addition, a reservoir or tank having an outletconduit 2l to the pump 22 which discharges into the pressure line 23terminating in the port 24 in the selecto-r valve I4, shown in greaterdetail in Figs. 5, 6 and 7. With the valve I4 in its central or neutralposition as shown in Fig. 1, corresponding to the position of itsmovable element as.

shown in Fig. 5, the fluid pressure discharged through the line 23 andthe port 24 passes through the open center of the valve, through theopposite port 25 and the return line 25, through which it is returned tothe reservoir 2li. The present hydraulic system is generally known as anopen center, or open neutral, hydraulic system for this reason.

The selector valve I4 is provided with a port 29 in communication withthe down pressure line 3i) extending to the actuating motor l5 and thevalve I4 is also provided with a further opposite port 2l which is incommunication with the up pressure line 28, connected to the oppositeend of the cylinder of the uid actuator motor i5. This actuating motorconsists of a cylinder portion 3i which is pivotally mounted upon theaircraftf-v structure at 32 and has reciprocable therein the piston 33which is pivotally connected at its outer terminal to the aforementioned1'iap actuating pivot I9. The selector valve I4 is provided with aninternal ported plug or movable element 34 which is xedly attached tothe external arm 35 by which it is rotated for selective. control of uidto either end of the iluid motor l5.

The control mechanism I3 includes essentially a handle or lever 35carrying a control detent 3l selectivelyv engageable with any of thepositions in the notched detent plate 38 which is suitably attached toadjacent supporting structure, 'Il in Fig. 3, by the brackets 39disposed at eachend of the arcuate plate 38. trol lever 36 also carriesa pawl 4B engageable with the no-tch or detent 4I in the arcuatefollow-up cam member 42 which is pivotally .mounted upon the adjacentsupporting structure by the pivot bolt 43. The follow-up cam 42 has adownwardly depending lever portion terminating in the pivot 44 by whichthe manual control mechanism i3 is interconnected mechanically, throughthe follow-up mechanism I 2, with the ap i0 at the pivot I9.

A ratchet element 45 is co-axially mounted upon the same pivot 43 as isthe lower terminal of the control lever 36 and the follow-up cam member42. The upper arcuate edge of the ratchet member 45 is provided with aplurality of teeth, and detent recess portions 46 corresponding to theangular arrangement of the recesses The conv in the detent plate 38. Acompression coil spring 4l is disposed about the base portion of thecontrol lever 36 and serves to urge the pawl 4B upwardly at all timeseither against the arcuate edge 42a of the cam member 42 or its notch 4I The lower or depending portion of the ratchet member is pivotallyconnected at 4B to the push-pull rods 49 and 50, by which the ratchetmember controls the selector valve I4, to which the rod 5 is connectedat the pivot 5I.

Between the push-pull rod members 49 and 50, there is disposed a bungeeor lost-motion member 52 which is a spring or other resilient devicedesigned to transmit predetermined forces through the rod members 49 and55, and to permit partial telescoping or extension of the lostmotiondevice when the valve I4 is moved to one of its limiting stops prior tocompletion of the movement of the ratchet member 45. This lostmotiondevice 52 will be described in greater detail in connection with thedescription of the showing of the device in Fig. 4. At the oppositeterminal of the rod 50, there is provided a resilient centering device53 which is pivotally mounted upon suitable supporting structure at thepivot 54. This centering device has the eITect of automaticallyreturning the movable element 34 of the selector valve I4, as well asits operating lever 35, to their neutral central positions whenevercontrolled movements of the ratchet member 45 are completed and theholding forces removed therefrom by release of the detent 45.

The mechanical follow-up assembly I2 comprises a push-pull rod 55 whichis pivotally connected at one terminal to the depending portion of thefollow-up cam 42 by means of the pivot 44. The opposite end of this rod55 is pivotally connected to a bell-crank lever 56 which is mounted forpivotation about the pivot 5l. The remaining arm of the bellcrank lever56 is pivotally attached to a link 58 which in turn is pivotallyconnected at its oppositeterminal to an arm of a further bellcrank 59pivotally mounted at the pvot 65. The remaining arm of the bellcrank 59is pivotally connectedto a pushpull rod 6I which is pivotally connectedat its opposite terminal to the above mentioned pivot I9 on the flap I,at which the piston 33 of the hydraulic actuating motor I5 is alsopivotally attached.

Figs. 2 and 3 show in detail the elements which comprise the manualcontro-l mechanism I3, which has been shown in Fig. l, and its moreessential elements described in connection therewith. The upper end ofthe tubular control handle 35 is provided With a knob or grip portion 62which is attached to the handle by the through bolt 63. The tubularhandle 36 is provided with a pair of slots 36a through its opposite Wallportions adjacent the above mentioned detent rollers 3l, which aremounted for rotation about the pivot pin 'I0 past which the lever ispermitted to move downwardly by means of these slots 36a. Thisoverrunning downward movement of the lever 36, which is necessary tomove the pawl 49 downwardly from engagement with the cam member 42, toengagement with the ratchet member 45, also permits the rollers 3l toremain engaged with the respective arcuate detent or notch 64 in thelower surface of the detent plate 38.

The lower portion of the lever E@ is externally reinforced by the tube65 which extends down to the upper end of a slot 36h in the tube 36 topermit vertical movement of the pawl 4G. Within 5 thellow-er end of 'thetubular lever 35, there is dis-- posed a bearing bloc-k 66 having alower aper- 'tured hub portion which is rotatably mounted eoncentricallyabout'the main pivot'bolt The upper portion of the bearing block de -istransversely slotted to Vpermit vertical movement of the pawl iii. 'Thelatter is provided with a xedly attached square pin di which extendsthrough the pawl across the spaceb'etweenthe two Ydivided upper portionslof the bearing block 68, 'which yis 'also provided with a slot 56a ineach side within which the extended pin portions 51 are permittedto'move vertically along the central axis of the lever 36, while at Athesame time being prevented `from lateral or rotational movements asviewed :i

'1in' 1-Beiieath the pin 10 kabout which the rollers 31 rotate, there isdisposed a washer de, and vafooin'p'ression spring 653 is disposedwithin the `inner tubulai` Ilever L35 for resiliently Vurging thebearing lblock t6 downwardly, while at the same time urging the washer$8 and the detent 'roller-assembly S31- 1d upwardly into engage-Vmentvvith the detent plate 318.

Inasn'iuchas'the bearing block 6E is maintained its downward 'xedposition by rotationalfengagementwith the hub assembly about the pivot233, the spring 69 Ycan only act or extend in the upward -direction andaccordingly resiliently maintains the rollers 31 Within the'desireddetent recess 64 from which they may be removed when 'the pawl '46 isvpushed downwardly from engagement with the notch 'si of the cam mem-VberllZ lbydownward pressure on the gri-planeo i512, 'whereupon therollers may be disengaged by fore or :aft rotational movement of thehandle about the pivot 4'3. Similarly itwillbe-ncted that the pawl ilmaybe 'disengaged `from thenotch 4I inithe segment 42 kby downward axialmovement of fthe 'lever -36 toward the pin 43 whereby the pawl 40'engages one ofthe 'notches fit in the ratchet 45 withoutdisenga'gementof the rollers di from the detent plate '38.

"The manual control mechanism as shown in Figs. 2 and 3, is supportedupon the adjiacent structural yframework 11 by vmeans o'f the bolts i4,TE and 115 and the two triangular-shaped "fixed plates `V1| Vand i2,through ythe corners of whichthe through-bolts 14,15 and l are passedjto clamp the assembly together. As indicatedin 'the sectional elevationin Fig. 3, these 'through- `'bolts Ipass through the plate elements 1iand T12 Aand as shown inthis gure in the case of the bolt T4, they alsopass 'through the plate 11 of the 'adjacent supporting framework. Abushing 13 is rconce'ntrica'lly disposed about the pivot pin dii,

'in'dicates a terminal rod which is threadedly connected tothe'push-pull rod 49 and extends 4through Vthe adjacent 'guide Yblock:portion '19 'of the device. The lost-motion device T52 is 'housed"within a casing portion 8D which is pluggedat its opposite 'endby afurther guide block Ei! which also has a threaded terminal portionextending vtherefrom Yfor 'attachment to the push-pull rod fell. Thecasing or shell 80 is attached to the 'terminal block 8l by means ofthethroueh-rivets :or 'pins B2 and'Za andtheblock is provided withFafreoes's. or. guide 'portion 8 I'a; 'The .I-'rod fend 11:8

J:has a *reduced vdiameter portion 33 terminating in a head Vportion 83aand at the ends of the reduced portion e3 are disposed washers orabutment elements Se and Y35. Disposed between these abutment washersare two compression springs iii and `3l coaxially arranged about thereduced-portiontd and adapted to resiliently loppose either.telescopingof the rod within the oasi-ne iii), or extension of the rod"i3 from within the casing.

in -other"words, as a force toward the right in Figs. l-1 and 4 'isapplied to the rod 18, the entire push-pull assembly dS---EZ will moveto the -right v.as :a xed length unit, `moving the valve arm 35 untilits limit stop (not shown) .isrea-Ched. in those adjustments of themanual control mechanism i3 where itis necessary to rotate the ratchetmember i5 beyond the throw Ior rotae tional'mo'vement of the valveelements 34 rand 3E, the1'esistanceoifered by the Yvalve stop will causethe rod 1d tocompress the springs dii and el, and to telescope withinthe casing di? to the extent oi the excess, or oven-movement, of the corrol lInechanism with respect to the selector valve throw. When theratchet member 45 is, howlever, again released, the centering mechanism53 will restore the Valve .to its neutral central position and thecompression in the springs 85 and el 'will cause extension of the rod4element Tie, and return of `the ratchet member d5 to its neutralposition, 'to restore the original length of 'the push-pull vrod.assembly lis-e-ef. 1

The operation of the hydro-mechanicalfollow up system shown in Fig. ylis as follows:

Let 'it be assumed that it is desired .to .move the Vnap iii to .its orup :position from the hal-down or 20 position shown in this figure. Withthe control lever 36 in its 20 or halfvdown position as shown in Fig. 1,and in the central yor Vneutral position of the valve arm 65, themovable element 34 and its relationship to Athe ports Aof thc valve i4are shown in the neutral position of Fig. 5. In this figure, it will benoted that the pressure line 23 from the pump l2,2 enters the valve port24 and passes through the center element 3d and out through vthe port22'5 4into the .return line 42F and back into the `reservoir 2%. Theposition of the central plug :element Slt interrupts any flow from theport 21 to the port .-E, or -vice versa, and the hydraulic motor i5 islhydraulically locked in the position shown by the inability of itspiston t0 displace `fluid into either conduit 28 or 3D. The knob G2isvdepressed and the control lever 36 is permitted to be moved forwardes the pawl 40 is moved down out of the notch 4i in the pivoted element42. As the pawl di? is moved down toward the pivot axis d3, it engagesone of the recesses 46 in the second pivotal ratchet element d5 which isconnected to the'control lever 35 of the selector valve id. The controllever 3B is then pushed forward past the 10 setting to the 0 or full lupsetting. As the lever 36 is initially moved forward, the pawi 4U ismaintained in the tooth recess 46 by the lower edge #32a of the arcuatecamxmember '42, and this forward movement lof the lever and vitsattached pawl 1Q causes lthe Yratchet element 45 to rotate in the samecounterclockwise direction about its pivot axis d3. This rotational.movement of the ratchet element 45 causes translation of the push-pullrod assembly iii-'5U rearwardly to the right and imparts vconcurrentcounterclockwise movement to the controllever 35 of the valve E4.

r .the 4'alterementioried forward movement 'of the control lever 36 andits attached pawl 40 is made to the or up position, the lever 35 of thevalve I4 is moved in the counterclockwise direction until the stops (notshown) on the valve I4 are reached, and the internal element 34 of thisvalve assumes the position shown in the up condition of Fig. 5. in theevent the valve stops are reached before the lever 33 can be movedthrough its full forward movement in Iwhich the roller detents 3l engagethe forward notch 64 in the detent plate 38, the excess movement of thepush-pull rod 49 is absorbed by the lost-motion device 52. This ispermitted by the partial compacting or telescoping of the element 18 asit moves forward into the recess 8Ia of the end block element 83 andcompresses the springs 86 and 81 to the required extent.

Referring now to Fig. 6, it Will be noted that the movable valve element34 has been rotated in the clockwise direction into the position inwhich the passage through the element is cut oi by the walls of the bodyof the valve and the ports 24 and 21 are placed in communication witheach other. With the parts of the valve I4 in this up position as shownin Fig. 6, the fluid pressure within the conduit'23 enters the port 24and passes out through the port 21 into the up pressure line 28 andthence .into the outer end of the cylinder 3i of the hydraulic motor Icausing the piston to be drawn into the cylinder toward the pivot 32 andimparting similar movement to the flap I0, causing it to rotate upwardlyabout its pivot I8. The fluid displaced from the forward end of thecylinder is discharged through the conduit 30, the ports 29 and 25, andthence through the return line 26 back to the reservoir 20.

Returning now to the manual control mechanism I3, it will be recalledthat as the pawl 40 was pushed downwardly out of engagement with thenotch 4I of the cam member 42, the latter was permitted to remain in theposition shown in Fig. 1, as the control lever 36 and the now engagedratchet element 45 Were rotated in the counterclockwise direction aboutthe pivot 43. As the flap IG, however, moves upwardly and forwardlyabout its pivot, the connected follow-up linkage 55 t0 Si inclusive, iscaused to be operated and this forward upward movement of the flapimparts counterclockwise rotation to the cam member 42 about the samepivot 43. It will therefore be seen that both of the elements 42 and 45are rotated about the pivot 43 in the same direction, with the positivepilot controlled forward movement of the ratchet member 45 preceding thefollow-up movement of the cam member 42.

It will be recalled that the ratchet member 45 is moved forward manuallyby the like movement of the control lever 3b due to its engagement ofits pawl 40 and once the latter is released downwardly from its detent4I, it rides forwardly against the inner edge 42a of the arcuate cammember 42, under the iniiuence of the spring 41. As the cam member' 42is, however, caused to follow-up the movement of the ratchet 45 as theresult of the mechanical follow-up linkage I2, the detent notch 4I againovertakes the pawl 4! at the forward up or 0 position, and the pawlagain is caused to move upwardly away from the pivot axis 43 out of thenotch 46 in the ratchet 45 and into the notch 4I in the cam member 42.As the pawl 40 is caused to move out of the notch 46 under the influenceof the spring 41, the ratchet member 45 is placed under the iniiuence ofthe resilient centering device 53, which returns the valve lever to theinitial neutral position as shown in Figs. l and 5. This rotation or"the movable central element 34 of the valve I4 back to the neutralposition shuts oi the how into the up pressure conduit 28, as well asany return now through the conduit 39, and the pressure from the line 23passes through the open center of the valve I4 to be returned directlythrough the conduit 26 to the reservoir 20. In this neutral position ofthe valve I4, the flap il) is accordingly hydraulically locked in its upposition and the follow-up mechanism also serves to mechanically retainthe nap in this position by virtue of the detent rollers 31 engaging theup notch 64 in the detent plate 38.

It will also be understood that by means of the system which has beenshown and described the flap I0 can also be moved up from its 20 to its10 position, and it is not necessary that movements from the half-downposition be made all the way to its full up position. In order to movethe ap up from the 20 to the 10 position, it is merely necessary todepress the knob 62 to release the pawl from its detent 4I and engagethe same in the ratchet 45, and to move thecontrol lever 36 forwardlyuntil the detent rollers engage the notch for the 10 position. As in theoperation toward the full up position, the pawl 40 is maintained inengagement with the ratchet by the cam member edge 42a and as the latteris caused to follow-up the movement of the ratchet member by themovement transmitted through the mechanical follow-up link- Aage as theflap is moved upwardly, the pawl 40,

which is continually urged outwardly away from the pivot 43 by thespring 41, is caused to move into and engage the notch 4I as the cammember reaches the 10 position. YAt this position, the ratchet member 45is released from the manual restraint and the restraint offered by thedetent rollers 31 within the 10 notch in the detent plate 33 and thisratchet member is again free torestore the lever arm 35 of the valve I4to its neutral position under the influence of the centering device 53.As this occurs, the actuating pressure from the line 23 is cut off andno .further movement of the flap by the hydraulic motor IE occurs. Thenap I0 is accordingly retained in this 10 position, both by thehydraulic locking effect of the blocking action of the element 34 of thevalve I4, as well as by the restraint offered by the detent rollers 31in the notches of the detent plate 38 exerted through the engaged pawland detent assembly I0-4I holding the cam member 42 and the mechanicallinkage I2 fixed in this 10 position.

The reverse movement of the flap is similarly accomplished by thereversal of the movement of the control lever 36 and the operation ofthe respective elements and their functions are the same as in theforegoing operation. From any position of the ap I0, it is merelynecessary for the pilot or operator to depress the control knob 62 todisengage the pawl 40 from its detent 4I, and to engage the oppositetooth in the ratchet member 45, and by swinging or rotational movementof the control lever 36 to the desired setting on the arcuate detentplate 38 it will be seen that the ratchet causes the valve to operate inthe required direction to permit ow to the fluid motor in the properdirection to move the nap into the desired position. As the pawl 4I] ismoved with the lever 36 andthe ratchet 45, the

In each one detent setting tothe next in the up direc- 'tion, issufcient to impart the required full anguflar movement to theY valve armand the mov- `.able element 3ft to cause the passageway in the movableelement to be cut off and to place ports 24 and 2, and ports 29 and25Ain communication respectively. When moved in the down direction theports 24 and 29, and ports 21 and 25 are placed in communication, I-twill also' be noted that where it may be necessary to move the controllever 36 from one extreme position to the otherthe excess, orovertravel, of the movement transmitted, by the ratchet. and .itspush-pull ,llod beyond the rotational angular movement Aof the arm 35,as permitted by the stopsof the valve lll, is absorbed bythe lost-motionor overriding devicel 52. Asl the ratchet member 45 is vagain releasedVby outward movement of the pawl du, the springs 86 and ill inthedevice52l again restorethe push-pull rod assembly ege-5l) to its originalAlength; and as the valve arm 3,5 is restored by the centeringassembly53to its central neutral position, as shown in Fig. 1, the il' ratchetmem-ber 45 is also ,returned to its central position as shown in thisfigure.

Other forms and modicationsof the present invention, bothA with respecttoits general arrangement and the details of its respective parts, areintended to come Within the scope and spirit of the present, inventionas more particularly denedin theappended claims.

Iiclaimr;

1 Ar remote:- controli system. comprising a controlled member movablymounted. upon a. supporting Structura a sourceof; fluidi DreSSure, ahydraulic motor operatively con.nectedy to said controlled member., aspring-biased; valve, conduit means connecting said source of; fluidDressure to said valve and to said hydraulic motor, manual controlmechanism including a pvotally mounted notched element operativelyconnected to saidV controlled member, a pivotally mounted ratchetlelement operatively connected to said valve, and manually-actuatablepawl means alternatelyY engageable with said ratchet element and saidvnotched element arranged for its automatic release from said ratchetelement and its engagement with said notched element to permit saidValve to return to its initial position under the innuence or saidspring-biasing; for stopping said hydraulic motor at a; predeterminedposition,

2. In a remote control, System, a movably mountedi member, a source offluid pressure, a hydraulic motor operatively connected to said movablemember and in fluid communication with said pressure source, a valve inuid communication with said pressure source and said hydraulic motor,biasing means for returning said valve to its neutral position, a manualcontrol assembly including a control lever movable about a pivot, a pairof notched elements rotatablev about said control lever. pil/Ot, a paWlmOV- ably carried byl said. control lever arranged for alternateengagement withv the notches ofeither of saidpivoted elements, a rst; ofsaidpivotally mounted elements operatively connected" to; Said movablemember, thev second off said pivotally mounted elements operativelyconnected to said vhydraulic valve, said pawl being manually operable tobe disengaged from the first of said notched elements for engagementwith the'second said notched element for the manual actuation of saidvalve arranged in such manner vthat movement of said control leveradjusts said valve for the actuation of said pivotally mounted member bysaid hydraulic motor, and means forv the automatic return of said pawlto engagement with said rst notched element for mechanically retainingsaid adjusted position of said member.

3. Ina follow-up control, a member pivotally mounted upon a structure, ahydraulic motor operatively connected to said member, a source of fluidpressure, a spring-biased Valve, fluid conduits operatively connectingsaid fluidy pressure. source with said valve and with said hydraulicmotor, a manual control mechanism including a shiftable paWl meansoperativelyco'nnected to saidyalve for the predetermined hydraulicpositioning of said member, 'said manual control mechanism including aratchet element engageable by said pawl means for the operativeconnection of` said control 'mechanism with Said selector valve, andfollow-up mechanism including a notched element engageable by said pavvlmeans operatively connected to said control mechanism and to saidpivoted member arranged to automatically cut-oil said fluid pressureflow to said hydraulic motor and said predetermined position of saidmember is retained by the shifting of said pawl means from said ratchetelement to said notched element.

4:. In a positioning system for a movable member; a movable memberpivotally mounted upon a supporting structure; a hydraulic motoroperatively connected to said movable member; a source of fluidpressure; a spring-biased valve for the control of said hydraulic motor;uid conduits in communication with said fluid pressure source., saidvalve and said hydraulic motor; a manually shiftable pawl; and manualcontrol means including a pavfl-engageable ratchet element operativelyconnected to said valve and a pavvl-engageable notched elementoperatively connected to said movable member arranged to hydraulicallyoperate said movable member to a pre-selected position and toautomatically stop said hydraulic operation when said pre-selectedposition of said movable member is reached by the shifting of the pawlfrom said ratchet ele, ment to said notched element.

5. In a follow-up controlV system, a controlled member pivctally mountedupon a supporting str-ucture, a source of uid pressure, a duid motoroperatively connected tov said controlled member, av spring-biased valvein fluid communication Vwith said uid pressure source and said fluidmotor, manual control mechanism .including a shiftable pawl and aratchet element engageable by said pawl operatively connected to saidvalve for the remote control of saidcontrolled member, and mechanicalmeansfincluding a notched-element engageable by said-pawl forinterconnectingv said manual control mechanism'with said controlled,member arranged upon overtaking movement ofsaid mechanical means withsaid mechanism and shitting of said pavvl from said ratchety element tosaid notched element to automatically interrupt said fluid pressure flowwhen said con.- trolled member has reached a predetermined position withrespect to the supporting structure.

a spring-biasedV valve in iiuid communication with said source of uidpressure and said motor,

a manual control mechanism including a lever 'carrying a spring-loadedpawl, a movable eleratchet element operatively connected to said 7. In afollow-up control system for the remote control of a movable member by ahydraulic motor, a source of iluid pressure for said motor, a valve influid communication with said source of iluid pressure and said motor, amanual control mechanism including a lever carrying a spring-loadedpawl, a movable element having a notch engageable by said spring-loadedpawl, said movable element operatively connected to said movable member,a ratchet element selectively engageabe by said pawl by manual forceovercoming said spring loading, said ratchet element operativelyconnected to said valve, said manual control mechanism arranged topre-select the hydraulically actuated extent of ymovement of saidmovable member by the positioning of said valve and to hydraulicallylock said movable member in said predetermined position upon engagementof said movable element notch by said pawl and the disengagement of saidpawl from said ratchet-connected valve, and resilient means arranged torestore said valve to its neutral position in which said fluid pressureis permitted to circulate through said valve and thel flow to said uidmotor is blocked in each direction.

8. A remote control system comprising a controlled member movablymounted upon a supporting structure, a source of fluid pressure, ahydraulic motor operatively connected to said controlled member, aspring-biased valve, conduit means connecting said source of fluidpressure to said valve and to said hydraulic motor, manual controlmechanism including a notched element operatively connected to saidcontrolled member, a pivotally mounted ratchet element operativelyconnected to said valve, said notched element and said ratchet elementmounted for independent pivotation about a common axis, andmanually-actuatable pawl means alternately engageable with said ratchetelement and With said notched element arranged for automatic releasefrom said ratchet element and its engagement with said notched elementto permit said valve to return under the inuence of said springbiasingto its initial position for stopping said hydraulic motor at apredetermined position.

9. A remote control system comprising a controlled member movablymounted upon a supporting structure, a source of uid pressure, ahydraulic motor operatively connected to said controlled member, aspring-biased valve, conduit means connecting said source of iluidpressure to said valve and to said hydraulic motor, manual controlmechanism including a pivotally mounted notched element operativelyconnected to said controlled member, a pivotally mounted ratchet elementoperatively connected to said valve, and manually actuatable pawl meansmounted for pivotal movement about an axis coaxiai with the axes ofpivotal mounting of both said elements alternately engageable with saidratchet element and said notched element arranged for its automaticrelease from said ratchet element and its engagement with said notchedelement to permit said valve to return to its initial position under theinuence of said springbiasing for stopping said hydraulic motor at apredetermined position.

10. A remote control system comprising a conj trolled member movablymounted upon a supporting structure, a source of fluid pressure, ahydraulic motor operatively connected to said controlled member, aspring-biased valve, conduit means connecting Vsaid source of fluidpressure to said Valve and to said hydraulic motor, manual controlmechanism including a pivotally mounted notched element operativelyconnected to said controlled member, a pivotally mounted ratchet elementoperatively connected to said valve, and manually actuatable pawl meansalternately engageable with said ratchet element for the manual controlof said valve and with said notched element arranged for its automaticrelease from said ratchet element and its engagement with said notchedelement to permit said valve to return to its initial position under theinfluence of said spring-biasing for stopping said hydraulic motor at aposition determined by the position to which said notched element may bemanually moved by said manually actuatable pawl means.

l1. A remote control system comprising a controlled member movablymounted upon a supporting structure, a source of uid pressure, ahydraulic motor operatively connected to said controlled member, aspring-biased valve, conduit means connecting said source of uidpressure to said valve and to said hydraulic motor, manual controlmechanism including a notched element operatively connected to saidcontrolled member, a ratchet element operatively connected to saidvalve, said notched element and said ratchet element mounted forindependent pivotation about a common axis, and manually actuatable pawlmeans alternately engageable with said ratchet element for manualcontrol of said valve and with said notched element arranged for itsautomatic release from said ratchet element and its engagement With saidnotched element to permit said valve to return to its initial positionunder the influence of said spring-biasing for stopping said hydraulicmotor at a position determined by the position to which said notchedelement may be manually moved by said manually actuatable paWl means.

JOHN P. ANDERSON.

REFERENCES CITED The following references are of record in the nie ofthis patent:

UNITED STATES PATENTS Number

